1. Field of the Invention
The present invention relates to a hydraulic controller comprising: a pair of liquid chambers; and an on-off valve capable of opening and closing a flow channel on the side of the liquid chamber with a higher hydraulic pressure out of the pair of liquid chambers, the flow channel being capable of providing communication between the pair of liquid chambers.
2. Description of the Related Art
Such a hydraulic controller is used, for example, to control brake hydraulic pressure in a vehicle braking system, and is disclosed, for example, in Japanese Patent Application Laid-Open No. 2002-308085.
The conventional hydraulic controller uses an on-off valve for a hydraulic booster in order to operate wheel brakes with boosted pressure. When an on-off valve is opened, brake fluid in the liquid chamber with a higher pressure flows into the liquid chamber with a lower pressure via a small-diametered flow channel. Since the lower-pressure liquid chamber is wider than the small-diametered flow channel, the brake fluid flowing from the flow channel into the lower-pressure liquid chamber causes an abrupt pressure change, thereby producing operating noise.